1. Field of the Invention
The present invention relates to a replacement-period detection method for detecting a replacement period of an actuator used in a vehicle control apparatus and a vehicle control apparatus provided with a control actuator of a motor, a solenoid, or the like, which can provide notification of the replacement period of the actuator.
2. Related Art
Conventionally, various types of control actuators which are driven by receiving a supply of electrical power are employed to control a traveling state or the like of a vehicle, such as a passenger car or a truck. For example, various types of control actuators such as an electrical pump motor to drive a hydraulic pump to supply brake-fluid pressure to a wheel cylinder, a solenoid (control valve) to control brake-fluid pressure applied to the wheel cylinder, and the like are disposed in a hydraulic circuit of a brake control apparatus.
A control actuator of this type ordinarily is periodically replaced at every certain interval (for example at a time of predetermined periodic inspection) so that breakdown does not occur during travel or the like.
For example, an electrical pump motor, when used for a prolonged period, wearing or the like of the brushes of the motor or of the eccentric portion of the pump drive unit may occur, or a solenoid, may leak brake fluid due to wear of a pedestal seal portion. Therefore, replacement of these control actuators at an appropriate time is important.
A usable period of a control actuator ordinarily becomes longer when an actuated frequency is low. However, depending on the vehicles (in particular with trucks) there may be a large disparity in travel distance (vehicle life). For that reason, there may be a large disparity in actuated frequency of the control actuator. As a result, when merely replaced periodically, even a control actuator which is still sufficiently usable may be replaced, and there existed a problem in that waste is increased.
Additionally, when a control actuator is designed to be suited to a vehicle having an extremely long traveling distance, a high-cost system results, which is not desirable.